The servant songs in Isaiah tell the story of humanity's need for a Saviour and God's plan to send one. In telling the story of the first servant in Isaiah 42, we find that just like the Israelites of Isaiah's time we are in the position of facing up to the consequences of the choices we make in life. We feel the weight of other peoples' choices affecting our lives and often carry guilt and shame about how some of our choices have affected others.
There's good news for people who don't always make great choices. God promised to send someone who would begin a transformation of humanity and would not stop until the work is finished. A transformation that does away with sin and all it's consequences so that only goodness remains. We can count on this servant to be successful in His mission because God has proven time and time again that He's not like the other things we often chase after in life. He is all powerful, all knowing and completely reliable to do what He says He will do.